"Our call for action urges researchers in academia, pharmaceutical companies and government to accelerate the development of chemopreventive agents," said Margaret Foti, Ph.D., Chief Executive Officer of AACR.
The AACR contends that the FDA should approve agents targeted to precancer, much as it has approved drugs to prevent other diseases. For example, the field of cardiovascular medicine was revolutionized when the FDA began to approve drugs such as lipid lowering agents to reduce heart attack risk, as opposed to directly preventing heart attacks directly.
"The AACR believes that reducing precancers lowers cancer risk, and that the FDA should take a similar stance regarding the approval of drugs for this condition," added Dr. Foti. AACR believes the link between some precancers and invasive cancers – particularly in certain high-risk populations – is so clear that drug developers should only be required to prove their proposed medicines are safe and effective in treating or preventing the evolution of precancer to cancer.
Aside from surgery, doctors now have limited options to treat precancers. Currently, only five agents have been approved by the FDA to combat specific precancers in patients with high-risk of developing cancers: topical 5-FU for actinic kerotoses, a precancer of the skin; topical diclofenic, also for actinic kerotoses; intravescial BCG, for bladder cancer; tamoxifen, for ductal carcinoma that leads to invasive breast cancer; and celecoxib, for adenomous polyps of the colon.
According to Dr. Foti, the pursuit of drugs to treat precancers has been slowed by several factors. "Science had not advanced far enough to allow clinicians to detect early cancers or to monitor the results of treatment on a molecular level." Today, however, emerging technologies for noninvasive imaging are increasing the number of lesions that can be detected and identified at an early stage. The development of the gene chip, for example, is allowing scientists and clinicians to measure specific cancer-related genomic changes in patients undergoing treatment. "Second, many also worried about the risks of giving medicine to seemingly healthy people – including those with precancers. However, this attitude clearly has changed with the treatment of other life-threatening conditions such as cardiovascular disease," Dr. Foti added.
For example, strong evidence links the presence of colorectal adenomatous polyps with the later presence of colon cancer, particularly when polyps are large and composed of more abnormal tissue. With prostate cancer, studies have shown that 40 percent of all patients with high-grade prostatic intraepithelial neoplasia (HGPIN) – and no detectable cancer – develop cancer three years later, with cancer incidence growing to 80 percent in 10 years.
"We need to evaluate what we now know about cancer prevention and move forward rapidly to make new investments in this research area. Only then can we develop the technologies and chemopreventive drugs that can stop or reverse the deadly process of carcinogenesis that starts with the diagnosis of a precancer, " Dr. Foti said.
Founded in 1907, the American Association for Cancer Research (AACR) is a professional society of more than 19,000 laboratory and clinical scientists engaged in cancer research in the United States in more than 60 other countries. AACR's mission is to accelerate the prevention and cure of cancer through research, education, communication and advocacy. Its principal activities include the publication of five major peer-reviewed scientific journals (Cancer Research; Clinical Cancer Research; Molecular Cancer Therapeutics; Molecular Cancer Research; and Cancer Epidemiology, Biomarkers & Prevention).